APOGEE-2

APO Galaxy Evolution Experiment North and South(APOGEE)

APOGEE-2 will extend the reach of the SDSS by using both the Sloan Foundation Telescope at Apache Point Observatory and the Irénée du Pont Telescope at Las Campanas Observatory in Chile. A telescope in each hemisphere means that APOGEE-2 will be able to see the entire Milky Way. The new Chilean telescope will offer an excellent view of the galactic central regions. Image credit: Dana Berry / SkyWorks Digital Inc. and the SDSS collaboration.

The APO Galaxy Evolution Experiment North and South (also known as APOGEE-2) will explore the formation history of the Milky Way using the “archeological” record provided by hundreds of thousands of its individual stars. The details concerning how smaller galaxies assembled so that the Galaxy grew from its progenitors are preserved in the patterns seen today in the motions of stars and the abundances of chemical elements that they contain. We will map these patterns using observations from the Apache Point site in New Mexico, and from the 2.5-meter du Pont Telescope at Las Campanas Observatory in Chile, obtaining a complete view of our Galaxy’s history. We are also collaborating with NASA’s planet-finding mission, Kepler, to measure the abundances of carbon, oxygen, nitrogen and iron in planet-hosting stars, to study the role that these elements play in the formation of terrestrial planets.

Key Science Questions

What is the history of star-formation and chemical enrichment of the Milky Way?

What are the dynamics of the disk, bulge and halo of the Milky Way?

What is the age distribution of stars in the Milky Way?

Are certain properties of stars associated with whether or not they have planets?

To answer these questions, we rely on stellar spectra taken at near-infrared wavelengths in order to gain a comprehensive view of (1) what are the abundances of elements in stars across our Galaxy, and (2) how stars in various locations are moving through space. These goals raise a number of questions. A good understanding of the science questions rely on other, preliminary questions being answered first.